A surprising reaction product

Chapter 26 revealed that sodium r COaMe NaCI 

However, using this reaction to decarboxylate the malonate shown here did not merely remove the C02Me group. Instead, a compound was formed with a much more complicated NMR spectrum than that of the expected product (which was known as it could be made another way). The NMR data for both compounds are detailed below. 

All that is left is C3H5 and this must be fitted in where the dotted lines go. One reasonable interpretation from the NMR would be two diastereotopic CH2 groups, one with 10 and one with = 5 Hz, linked by a CH group. 

If this is the case, what has brought the values of down from 14 to 10 and even 5 Hz Electronegative elements can t be the culprits as the only one is nitrogen, but small rings could. If, in fact, we simply join these two fragments together in rather a surprising way (the dotted lines show how), we get the correct structure. 

In this case, the geminal couplings d6 not help to assign the stereochemistry—the three- and five-membered rings can only be fused ds (just try making a model of the trans compound )— but they do help in assigning the structure. 

Chapter 26 revealed that sodium p, c02Me chloride can be a surprisingly pow-erful reagent. It removes ester C02Me groups from malonate derivatives, like this. 

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Treatment of [PtMe,cod] with Y(pz)3, where Y = HB or C, gave the expected products [PtMe2(Y(pz)3)]. However, these underwent a surprising reaction in refluxing pyridine to give square-planar products in which one of the pz rings was bonded to the metal via the C-5 carbon atom as shown in (42).39... 

At least 20 p.p.m. of nickel (TEA basis) are required in order to obtain 97 to 99% displacement within 2 hours (200° F., 2000 p.s.i. of ethylene). After completion of the reaction, when the ethylene pressure is released, a displacement reaction product containing traces of nickel catalyst tends to revert to alkylaluminum. This reaction takes place slowly at room temperature and atmospheric pressure, but the rate accelerates at the conditions required for TEA-olefin separation. It is no surprise, then, that even after only a few seconds contact a significant amount of back-alkylation will take place. 

Catalytic tests for cyclohexene oxidation show some activity of SnAlPO, which can be increased by cation-exchange modification. Cyclohexenone is a predominant reaction product. The difference between activity of SnAlPO and AlPO-5 is not very substantial, which is rather surprising. Considering the presence of tin and the transition metal cation, one could expect higher activity for oxidation reaction. Other catalytic investigations are under way and will be published [7]. 

Quite a surprising reaction has recently been reported [74]. With a catalyst of palladium metal on carbon in aqueous phase, propene is oxidized with oxygen to give acrylic acid, probably via allyl alcohol in a allylic-type oxidation (for allylic oxidation see Section 3.3.14). In the presence of chloride or oxidants the normal Wacker-type reaction product acetone arises. 

In a surprising reaction, A/,A/ -diphenylmethylene diamine (a possible intermediate formed in the commercial production of TDI, see Section 4.7.1.1) reacts with phosgene by cleavage of a carbon-nitrogen bond to give a mixture of products [2086] ... 

As with the other surface reactions discussed above, the steps m a catalytic reaction (neglecting diffiision) are as follows the adsorption of reactant molecules or atoms to fomi bound surface species, the reaction of these surface species with gas phase species or other surface species and subsequent product desorption. The global reaction rate is governed by the slowest of these elementary steps, called the rate-detemiming or rate-limiting step. In many cases, it has been found that either the adsorption or desorption steps are rate detemiining. It is not surprising, then, that the surface stmcture of the catalyst, which is a variable that can influence adsorption and desorption rates, can sometimes affect the overall conversion and selectivity. 

The combination of carbonylate dianions with silicon tetrachloride leads in high yields to the p-Si compounds 22-24. As already mentioned, the reaction can be performed either stepwise with isolation of the dichlorosilylene complex or in a one-pot procedure. The resulting products show a surprisingly high thermal... 

High product selectivity is one of the most important challenges in synthetic methods. Some electrode reactions of organic substrates show a surprisingly high chemoselectivity and regioselectivity Diastereoselectivity is occasionally observed,... 

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